I mean, let's be real: some people's employers have little sense of boundaries, so this could happen with some frequency. Same with people with complicated home lives and things involving children. How much tolerance should they be extended? I'm betting the answers there would vary considerably if people were honest.
People with such concerns rarely can commit to our schedule of weekly games, so it isn't an issue. We try, again and again, but ultimately they realize the constant interruptions and/or absences are interfering with the group's fun, so they bow out. If they are otherwise decent players, there is always an opening if their concerns change and they want to try again.
So, let's use my example one above: someone wants to play but mentions he's subject to unpredictable emergency calls from his work. Now what?
He probably doesn't play. He might hang out, or if it is a lone individual who is otherwise committed to playing, often another player or myself will run his PC in his absence, even texting him for important decisions if necessary.
For example, we had an engaged couple. The guy had a job where is would frequently be late or call to say it couldn't make it. His partner would play the PC as a second character until he showed up or for the session. So, because another player was willing to shoulder the responsibilty of a second PC, it worked out fine. Outside of game time, she could update him on everything, so it wasn't an issue.
So, if someone wants to play, is actually taking the time to learn how to play, shows up (when the actually show up), and is all-around a good player otherwise, we try to make it work. Sadly, there are times when such a player decides to bow out anyway. And course, there are times when no matter what we try, it is evident the player isn't doing what they can to in order to make it work, it's disruptive, and we let them go.
Whew... I am so relieved!
